The present invention relates to a dielectric resonator device which may be used as a filter or an oscillator in microfrequency regions.
There is a known dielectric resonator device in which a dielectric resonator element is mounted on an inner base wall of a shield casing via a supporting member. An example of such a dielectric resonator device is illustrated in FIG. 1. As will be seen in FIG. 1, it comprises a dielectric resonator element A of a circular or rectangular shape in cross section, a metal casing B for containing the resonator element A and an insulating holder member C made of alumina or forsterite. The resonator element A is mounted on the base portion of the metal casing B by the insulating holder member C so that the resonator element A has a desired Q-characteristic. The resonator element A is connected with the insulating holder member C by means of a heat-resisting adhesive layer D of an adhesive containing a glass glaze as a main component, silica containing adhesive or the other adhesive.
When the resonator device is operated, the resonator element A is self-heated with the resonance thereof. In particular, when the resonator is actuated with higher power, the higher the operation frequency is the larger the heat release value in the resonator element.
The heat-resisting adhesive layer D has a poor heat transfer efficiency because it contains air bubbles. Therefore, the heat-resisting adhesive layer D makes it difficult to transfer the heat in the resonator element to the insulating holder member C.
There may occur a heat-accumulation in the resonator element A so that it has a higher temperature. As a result, there may occur a pull-up between the resonator element A and the insulating holder member C or between the metal casing B and the insulating holder member C, and the resonance characteristic of the device may be varied.
Further, since the insulating holder member C is provided for mounting the resonator element A on the base portion of the metal casing B, the number of parts is increased and it is necessary to connect the resonator element A with the insulating holder member C, which results in expensive device.